Looking at long-term U.S. alfalfa yield trends can be depressing since there’s been so little increase over the decades. Not that there hasn’t been any, but it pales compared to the tremendous yield gains of corn and soybeans. Genetic improvements in alfalfa quality have also been very slow in arriving, in great part because of the stubborn linkage between yield and forage quality. N-R-G, the variety developed and released by Cornell University, is a good example. It offered higher forage quality, but at the expense of yield. Looking at its performance in alfalfa variety trials was discouraging…and university plant breeders acknowledged how difficult it is to break that yield/quality linkage.
However, it now appears that new alfalfa varieties have recently been released that combine reliably higher forage quality with equal or better yields. These are reduce-lignin varieties, and anyone who know anything about ruminant nutrition realizes that while some lignin is needed to keep plants upright, too much reduces intake and therefore animal performance. These new alfalfas–and there are both GMO and conventionally-bred varieties available–accumulate lignin at a slower rate, so at the early bloom stage have about as much as “normal” varieties at the late bud stage. This means that farmers have another 5 to 7 days for the alfalfa to grow (and increase yield). It also means more time for it to accumulate root reserves, which should have an impact on stand life. One of the more significant results may be a reduction in the number of harvests per season. One fewer harvest means less labor, fuel, equipment wear and tear–and less crown-damaging wheel traffic. Time will tell, but at this point higher seed cost appears to be about the only drawback to reduced-lignin varieties. We still have a lot to learn about managing these varieties including whether cool-season forage grasses can be growth with them, but so far, so good.